Glutamate turnover and the feed-in of various labeled precursors into glutamate pools in the dorsal sensory neuron are being analyzed. The role of the cell body and axoplasmic flow as well as local synaptic pools of glutamate are being weighed. There would appear to be a rapid proximodistal convection of glutamate and glutamine toward the synapse in the spinal cord from the cell body and axon with continuous turnover of glutamate and formation of new glutamate by key precursors such as aspartate, acetate, and glucose in transit down the axon. Glutamate conversion to glutamine is extensive, while glutamine conversion back to glutamate is very low in the resting state. Glutamine also is flowing rapidly down the dorsal root axon toward the synapses in the spinal cord. The nature of glutamate compartmentation has been defined in the dorsal sensory neuron and compared to other key neuronal tissues. Presently, the relationship of free glutamate to Krebs cycle activity and intermediates is being further analyzed in relation to maintaining transmitter levels of this amino acid.